Back in the '70s, our geography teacher took great pains to tell us that both Mrs and Miss were abbreviations of Mistress. In turn that is derived from the latin 'magister', becoming Maister, then Mister, or Maitre in french.
In Hardy's Mayor of Casterbridge, the farmers at the market are referred to as Maister (from memory).
Since I was married, I've been Mrs (Ms hadn't been invented, and like other posters I find it ugly), and now I've been Mrs longer than I was Miss.
In rural France, I'm Mme maiden name, nom d'époux married name. My gp thinks to flatter me by calling me Mlle. Which, tbh, smacks of accusing a (sadly) middle-aged woman of being an elderly virgin, generally taken to be rather insulting.
I follow the rule I learned at school of calling all women Mme, above a certain age, especially in a professional capacity. I've come across one example, a social worker in her late 20s, who rather aggressively corrected me with a forceful 'Mademoiselle'